1. Field of the Invention
The present invention relates to a display apparatus. More particularly, the invention relates to a display apparatus properly applicable for automobiles, in which a displayed image is observed via a reflection member such as a mirror as a virtual image.
2. Description of the Related Background Art
There are conventional display apparatus for automobiles to let a driver visually recognize driving information of a speedometer, a tachometer, and others, in which a display unit is installed on a dash board plane such that the driver can observe the displayed image of the display unit as a direct real image. The display apparatus of this type have such a problem that the external light from windows of automobile reflects on the surface of display unit to shine, thereby disturbing the driver's view. Also, there is another inconvenience that the driver requires a substantial time to focus on the display unit upon sudden change of view from an outside view to the display unit because the distance is short between the driver and the display surface of display unit.
For this reason, there are used display apparatus of a type as shown in FIG. 3 in which a light emission type display unit 1 comprising fluorescent display tubes is disposed in a dash board 3 such that a display surface 1a faces up, and a mirror 2 is disposed as a reflection member such that a reflection surface thereof faces the display surface la of the display unit 1, whereby the external light is prevented from directly impinging on the display unit 1 and the mirror 2 reflects the display light of the display unit 1 towards a viewpoint 6 of a driver, so that the driver may observe a virtual image of the displayed image of the display unit 1 far beyond the mirror 2.
The automotive display apparatus of this type has a telltale unit 5 for indication of warning, usually installed in a meter pad 3b of the dash board 3 as shown in FIG. 3, whereby the warning indication may directly be seen by the driver. FIG. 4 shows another example in which the telltale unit 5 is mounted in the meter hood 3a of the dash board 3 to face downward so that light from the unit is reflected at a transparent front plate 4 made of glass or acrylic resin then to be led to the viewpoint 6 of driver. The image is seen as a virtual image by the driver.
The conventional automotive display apparatus as shown in FIG. 3 shows a virtual image of display of speedometer and etc. of the display unit 1 at a distance, but has a problem that it is difficult for the driver to focus on the warning indication because the telltale unit 5 is relatively closer, which leads to a substantial difference of display distance. Also, the automotive display apparatus as shown in FIG. 4 is improved in difference of display distance, but requires a precision of parts such as a precision of surface of the front plate made of acrylic resin in order to reflect the light from the telltale unit 5, which results in increase of production cost. It is another problem for both conventional display apparatuses that the mounting position of the telltale unit 5 is separate from that of the display unit 1, which results in uneasiness of assembly.